Well, for such huge maps and such a large number of civs you can obviously expect a slow game. But to speed things up, you can do the following things:
- make sure you don't have any programs running in the background (use Start>Run>msconfig to disable unnecessary background tasks at start-up and Ctrl-Alt-Del to do so at runtime)
- in the game, set Unit Speed to maximum and disable showing enemy moves (as noted by Maq and cen)
- get more RAM: a fast CPU is nice but the amount of RAM is in this case far more important; for enormous maps with 30ish opponents you'll want at least 512 MB, maybe even more (don't have much experience with such big games myself)
- update your video and chipset drivers: doesn't always help but it never hurts either
Hmm, I had one or two other things but I seem to have forgotten about them. Will post them when they come back to me